A Foreign Office whistleblower who leaked secret documents to raise concerns about the government’s terrorism policy is set take on his former bosses at an employment tribunal.

Derek Pasquill is seeking compensation for loss of earnings and injury to feelings at the tribunal in central London, which is scheduled to last five days, the Press Association has reported.

An Old Bailey judge acquitted Pasquill in January 2008 on six charges that he breached the Official Secrets Act by making disclosures damaging to international relations by passing confidential papers to the Observer and New Statesman.

But the Foreign Office continued disciplinary proceedings against him and he was sacked in August of the same year.

Pasquill, who was suspended for 31 months before his sacking, believes he was dismissed for making leaks that were in the public interest.

The leaked documents showed the UK’s engagement with what Pasquill saw as radical Islamic groups over a number of months in 2005 and 2006.

A Foreign Office spokeswoman said: “The FCO strongly denies any allegations that Derek Pasquill was dismissed for making a public interest disclosure.

“His dismissal from the FCO was as a result of his gross breach of trust and wilful failure to raise his concerns under procedures available to him. He was dismissed under our internal misconduct procedure which is based on best practice.”